Everything to know about the Wi-Fi technology

Now a days every body is familiar with Wi- Fi without knowing the technology behind it . Day in and day out , people are using Wi- Fi at homes , in offices , at public places to connect to Internet and surf the Net . Wi- Fi technology is highly cost effective , convenient and at the same time provides good speed . At present , 51 % of mobile data traffic is being offloaded to fixed networks through Wi- Fi.

Wi- Fi is a technology used to set up wireless local area network. Wi- Fi enables to provide Wireless Local Area Network ( WLAN ) . WLANs are similar to LAN in fixed line networks; the important difference between the two is the nature of media . In Wireless LAN , media is wireless whereas in LANs , the media is a physical cable . Wi- Fi technology and LAN has been developed by Institute of Electrical and Electronics Engineers ( IEEE ) .

A simplified set up of Wi- Fi is shown in figure 1 . The devices communicate with Access Point ( AP ) for exchange of data among each other . AP is a wireless device connected to Internet via cables or wireless . Transmission power of an AP is low , hence area covered by an AP is small . To increase the area , more than one APs of the same operator are deployed.

An AP is identified by its identity called Service Set Identity ( SSID ) .AP continuously transmit its SSID to facilitate the user to identify the desired network . SSID is generally given a simple name like TAIPA , Jains, etc.

When a user comes in the area of Wi- Fi hotspot , his device searches and presents the SSIDs of networks available in the hotspot. The user then selects his desired network . The network then authenticates the device by exchange of shared key etc ; thereafter , device attaches itself to the network . Device and network also activate the encryption features for data exchange . Encryption allows secured data exchange and integrity of data is protected.

Now a days ,a fully integrated router having Access Point , connection for broadband connectivity , connection to Wireline Ethernet etc are available.

Wi- Fi History

Over a period of time , Wi-Fi technology has evolved considerably . First Wi- Fi 802. 11 Standard was launched in 1997 which offered 1-2 Mbps data speed in 2. 4 GHz band . Then came 802. 11a which enabled a data speed of 54 Mbps in 5 GHz band .

The real breakthrough in Wi- Fi technology came when 802. 11b was launched in 2000 which provides 11 Mbps using unlicensed 2. 4 GHz Industrial , Scientific and Medical ( ISM ) band . 802. 11b provided backward compatibility and hence became popular very soon.

Subsequently came 802. 11 g which provided 54 Mbps in 2. 4 GHz band.

802. 11n which provides 450 Mbps and operates on both 2. 4 GHz and 5 GHz band , came in market in 2007 . The latest standard is 802. 11 ac which uses 5 GHz band and supports a data speed of 1. 3 GHz. IEEE has introduced MIMO –“multiple input multiple output” technology in 802. 11ac which provides higher speed through several independent data streams between the sender and the receiver. In addition , 802 . 11ac uses wider channels of 80/ 160 MHz, and beam forming technology to support higher speeds. Now a days 802. 11ac Wi- Fi standard is common on tablets and is increasingly being provided on smart phones.

802.11ad standard based devices are expected to hit the market very soon . 802. 11ad standards support multi-gigabits speeds.

A very important feature of Wi-Fi technology is that all Wi-Fi compliant devices are interoperable i. e. newer version having enhanced features are compatible with older versions ; also devices of different vendors are interoperable . This feature of Wi- Fi along with unlicensed bands of 2. 4 GHz and 5 GHz make it very cheap and attractive for broadband connectivity.

Hotspot 2. 0 provide the technical standards for Next Generation Hotspots . Passpoint is a Certification which certifies compliance to Hotspot 2. 0 and hence ensure interoperability between Wi-Fi devices of different vendors . In other words , Passpoint certified devices are interoperable . Hotspot 2. 0 standards are based on a set of protocols called 802. 11u .

In Wi- Fi networks that do not support Passpoint , users have to search and choose a network , make a request to the AP/ network for connection each time and in many cases , are required to re-enter their authentication credentials ( Password/ Security key ) also . This obviously is a very cumbersome process and many times result in to denial of access to Wi- Fi AP for a variety of reasons .

Passpoint certification automates that entire process of attaching to a Wi- Fi network ; here network discovery , selection and attachment to the best network has been automated . A Passpoint certified device gets automatically attached to the best Wi- Fi network at a given location . Further the authentication is highly secured and based on WPA 2 Standards on the lines of GSM networks

Wireless Broadband Allianze ( WBA ) has also developed Wireless Intermediatery Exchange ( WRIX ) which enables interconnection of hotspots of different operators both nationally and internationally and facilitates roaming across wi- fi networks of different vendors . In addition to Wi- Fi roaming , WRIX standards also provide authentication of the roaming subscriber by interacting with his Home network.

“WRIX also facilitates settlement of accounting of usage of Wi- Fi services between visited network and home network and billing the roaming subscriber by the Home network who has used the Wi-Fi hotspot while roaming . This arrangement of billing the roaming subscriber and settlement of accounts between visited and home Wi- Fi operator is on the lines of GSM networks .In GSM networks , account between the two operators is settled through a third party - clearing house –and here it is done by WRIX owner .

Europe and US have deployed Wi- Fi hotspots in a massive way . There are millions of hotspots in these countries having roaming services among them . A mobile subscriber roams freely using the roaming features. There are independent third party global vendors offering Wi-Fi services through Hotspot 2. 0 and WRIX e. g. M/s Accuris Networks , BSG Wireless , Point Dume , Syniverse and iPass etc.

M/s iPass provides access to 53 million hotspots world wide across 120 countries . Similarly , M/s Boingo has roaming arrangements with more than 140 operators in more than 100 countries for Wi- Fi roaming . It provides hotspots worldwide at airports, universities, transport, restaurants, malls, stadiums, public spaces etc.

M/s Fon of UK , offers a unique plan to its community of Wi- Fi users by which a consumer can give part of his Wi- Fi bandwidth to general public M/s Fone also facilitates a travelling member of the group to use his Wi- Fi bandwidth at a new location while on the move.This arrangement has been named as Crowdsourcing of Wi- Fi . The service is provided through an encrypted Fonera router . M/s Fon have named its Wi- Fi AP as Homespot.

Carrier Grade Hotspot:

Seeing the use of Wi- Fi in handling data at high speed and at comparatively cheaper rates , Carrier Grade hotspots are being developed which will replace the best effort APs . Carrier grade Hotspots support real time applications like voice and video on the lines of 2G / 3G etc.

One significant development in Wi- Fi technology is that it has now been integrated fully with 4G – LTE and forthcoming 5 G networks .There would not be standalone Wi- Fi hotspots instead Wi-Fi hotspots would be integrated with mobile network .Mobile device will shift from 4G to Wi- Fi and vice versa as the user moves depending upon the configuration by the mobile operator in his network , thereby providing seamless connectivity , higher speed & throughput to the user.

LTE-U is being developed to work in unlicensed bands 5. 0 GHz which is termed as LTE-U .It has generated lot of controversy and competition between LTE providers and Wi-Fi technology providers.

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